That must be why it was so prevalently used in Saturn and PSX games. I mean with the competition being what it was back then these companies were sure to hop all over such a well known feature.
The Atari 8-bit was doing it back in the early 80s. It could have done so in 79 when released given the right software. I had several games which would play music and animations while loading data at the same time.
Lots of shit on the PSX did it too. Sorry I don't recall the game I had back in 96, but it streamed background data from the CD while superimposing a 3D ship and the objects you would shot at to destroy.